refactor(pages): 引入 Page Object 模式重构全部页面模块，变量统一为 snake_case

将原始 Selenium 操作脚本重构为三层 Page Object 架构：
- Page Objects（LoginPage/ReserveView/RecordsView/MainShell）
- Component Objects（Overlay 基类 + SeatMapOverlay/ReserveResultDialog 等对话框）
- Flow 状态机（ReserveFlow/CheckinFlow/RenewFlow）
- Services（CaptchaHandler/ReserveValidator/RecordChecker）

变量命名统一为 snake_case，方法名保持 camelCase，类名保持 PascalCase。

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/pages/flows/_helpers.py

@@ -0,0 +1,85 @@
+# -*- coding: utf-8 -*-
+"""
+Copyright (c) 2026 KenanZhu.
+All rights reserved.
+
+This software is provided "as is", without any warranty of any kind.
+You may use, modify, and distribute this file under the terms of the MIT License.
+See the LICENSE file for details.
+"""
+from datetime import datetime
+
+
+def timeStrToMins(
+    time_str: str,
+) -> int:
+
+    hour, minute = map(int, time_str.split(":"))
+    return hour * 60 + minute
+
+
+def minsToTimeStr(
+    mins: int,
+) -> str:
+
+    hour, minute = divmod(int(mins), 60)
+    return f"{hour:02d}:{minute:02d}"
+
+
+def findBestTimeOption(
+    time_options: list,
+    target_time: int,
+    max_time_diff: int,
+    prefer_earlier: bool,
+    is_reserve: bool = True,
+) -> tuple:
+    """
+        Find the best time option from available WebElement options.
+
+        Returns:
+            (bestElement, bestText, actual_diff, freeTimesList)
+            or (None, None, None, freeTimesList) if no suitable option.
+    """
+
+    free_times = []
+    best_time_diff = max_time_diff
+    best_actual_diff = None
+    best_time_opt = None
+
+    for time_opt in time_options:
+        if is_reserve:
+            time_attr = time_opt.get_attribute("time")
+            if time_attr == "now":
+                now = datetime.now()
+                time_val = now.hour * 60 + now.minute
+            elif time_attr and time_attr.isdigit():
+                time_val = int(time_attr)
+            else:
+                continue
+        else:
+            time_attr = time_opt.get_attribute("id")
+            if not (time_attr and time_attr.isdigit()):
+                continue
+            time_val = int(time_attr)
+        free_times.append(
+            time_opt.text.strip()
+            if not is_reserve
+            else minsToTimeStr(time_val)
+        )
+        actual_diff = time_val - target_time
+        abs_diff = abs(actual_diff)
+
+        if abs_diff < best_time_diff or (
+            abs_diff == best_time_diff
+            and (
+                (prefer_earlier and actual_diff <= 0)
+                or (not prefer_earlier and actual_diff >= 0)
+            )
+        ):
+            best_time_diff = abs_diff
+            best_actual_diff = actual_diff
+            best_time_opt = time_opt
+
+    if best_time_opt is not None:
+        return (best_time_opt, best_time_opt.text.strip(), best_actual_diff, free_times)
+    return (None, None, None, free_times)